As discussed in U.S. Pat. No. 5,947,073 to Chaffin et al., it is conventional to join plastic automotive air intake assemblies by means of linear vibration welding. Linear welding requires a relatively flat or 2-dimensional mating surface between the upper and lower housing parts. The two parts are placed within a vibration welding fixture and subjected to lateral displacement causing the mating surfaces between the parts to heat, soften, and fuse to one another.
In the case of highly contoured or 3-dimensional parts, vibration welding has proved unsatisfactory because of resulting lateral or linear displacement, creating weakened gaps in the vertical portions of the welds. The Chaffin patent teaches using a high frequency RF field to dielectrically heat an adhesive for bonding a first member tongue edge portion to a mating groove surface of a second member. The patent discloses an apparatus including a first continuous electrode that overlies the mating surfaces of the housing members. While the fabricating method of the Chaffin patent results in satisfactory welds, its use in the mass production of automotive parts is expensive as to labor and tooling costs as well as time consuming.